Grim Tales: Son of the Underworld
by Neon dagger
Summary: Jr. the Prince of death and son of Evil incarnate and unknown adopted and made deaths heir in this Fanfic we explore the possiblity of HIM being Jr.'s biological father
1. Chapter 1

Son of the underworld

Grim tales AU idea by AkumaKami64

Jr. held his head up sharply and glared at his mother filled with a sudden rush of courage, will power, a bit of hate for his mother although he wasn't quite sure why he felt the last one.

Suddenly Mandy was in front of Jr. and she sucker punched him square in the jaw making the boy stumble back as the Red on Mimi jumped much to the shock of everyone watching.

Mandy for a brief moment was stunned and it cost her 'Mimi's' Red lunged and clung to Jr. before Mandy had a chance to activate the containment procedure.

No one could move as Jr.'s body became wrapped in a crimson cocoon of sorts and before anyone else could move a deep crimson almost black tentacle shot out of the cocoon and broke the controls to the room that Mandy was about to use before returning to the cocoon.

After a moment to process what just MiniMandy stepped forward and asked "Mother what has happened to my dearest brother?!"

Mandy scowled as she looked over the controls one last time before addressing her daughter "Jr. has been reunited with his Red."

MiniMandy raised her eyebrows in shock and her eyes shifted between the cocoon and her mother as she spoke "What are you talking about mother?"

Mandy let her eyes roam to her daughter passing over Grim whom was glaring heatedly at the Red that incased their son before she replied to her daughter "MiniMandy you understand that Grim isn't your biological father… he is not Jr.'s either Jr.'s biological father is HIM."

MiniMandy's jaw dropped and Mimi whom was just now getting her bearings together stared at the cocoon a bit of worry in her eyes before MiniMandy spoke "But how is that possible Jr. lacks the Red and the other common features of the devil race?"

This time Grim spoke "Dats because your Mother had him aborted so he could become my son and heir…she traded the power of sins for the powers of death but I don't know how Jr.'s Red is still alive it should have died when he was aborted since Red needs flesh to bond to."

MiniMandy stared at the cocoon a moment before looking back at Grim "So what'll happen now?" Grim raised his shoulders and as they lowered the cocoon began collapsing in on itself leaving a relatively unchanged Jr. whom began walking towards the group.

As he moved forward his changes became more apparent his limbs or his fingers at least were fused together but still worked like it had joints and was deep crimson and were clawed, his hair was now black with a faint red tint, as Jr. got closer everyone took notice of the sharp teeth that took the place of his original set when Jr. smiled, his eyes were playful but held a shade behind them and as his eyes passed over each of them they felt Jr.'s pull on their sins making his smile increase as he saw Grim and Mandy frown.

Jr. spoke "What happens now dear sister is our dear mother here is going to let us go and take our new little pet with us." as Jr. spoke a deep crimson tentacle formed and wrapped around Mimi pulling closer.

Once Mimi was beside him he looked her over and his smiled widened slightly as he spoke again "Hello my sister from another mother."

Mandy stared at her son she knew he was a little spineless and that for someone born in hell he was just a little too normal a little too human but to think that having his Red would make him like this.

It probably shouldn't have shocked her as bad as it did but when his eyes grazed her see felt as if he was already planning on how to dismantle her kingdom and get rid of her in the process.

Jr. tilted his head and his eyes almost seemed to gain a soft edge and his smile became slightly softer as he spoke while tilting his head towards Mimi "Hey mom would it be ok if I had a pet?"

Mandy looked at her son before she simply nodded yes and gestured for him to leave making his smile return.

He walked off savoring the anger he felt rolling off his mother and father while also basking in the jealousy and lust coming from his blond sibling.

The boy made it to the door to Mandy's vault before he turned and faced the group before addressing MiniMandy "Hey Mini would you care to join me?"

The blond ragdoll cautiously nodded and jogged to him making sure to only glare at his captured 'pet' when he wasn't looking.

Switch to Mimi view

Mimi was cautiously optimistic when she was bonded to her half-brother's Red it did nothing but hurt her be it physically with the assistance of their father or mentally by constantly making her relive the pain in her dreams.

However when she met Jr. for the first time in the middle ground she was rightly shocked at how regretful and heartbroken he was over the loss of his sister and thus came to a conclusion.

Jr. was as kind as he was because he wasn't exposed to his Red and his Red was so cruel because it wasn't bonded to its master.

It had no natural restraint and HIM did everything he could to encourage that as without its proper host the Red needed to subsist off of the cruelty and around itself.

So when the two finally came to together that Jr. wouldn't become like HIM just a more…exuberant and violent version of himself.

Mimi suddenly jerked back and forth slightly as Jr. and his blond sister came to a stop in front of a door which Mimi took to be Jr.'s room as he proceeded to open the door to the room and entered after allowing his other half-sister to enter before himself.

Back to all view

Jr. gestured for MiniMandy to sit on his bed as he closed his door making sure that Mimi was inside the room and that he didn't shut his tentacle in the door.

After locking the door Jr. set his black haired sibling down and walked closer to her before lifting her stubs to chest level Jr. seemed to contemplate something before the deep crimson flesh crawled across Jr's limbs and wrapped themselves around Mimi's stubs before dethatching from Jr.

After a second Jr. in Nergal said something Mimi translated to 'become hands' and just like that the red Nergal flesh became a pair of slightly clawed hands.

The girls in the room where shocked Mimi was half expecting the boy to command the hands to choke her but he didn't the boy just stepped back and looked at the two girls in the room a devious smile on his face.


	2. Chapter 2

Son of the underworld

I don't own Grim Tales

Grim tales AU idea by AkumaKami64

Recap

The girls in the room where shocked Mimi was half expecting the boy to command the hands to choke her but he didn't the boy just stepped back and looked at the two girls in the room a devious smile on his face.

Currently

Jr. couldn't help but admire the two girls in front of him some despite being so young and being related to both of them they were still lookers.

Jr. paused a moment as he got closer to Mimi before getting behind her and running his hands over her sides from her hips up to her chest gently brushing his sister's developing chest as he did so earning a bit of ire from Minnie as she watched from his bed.

However, before she could try to say anything Jr. spoke for the first time since entering the room "Tsk tsk dear sister you are under fed we must get you something…" Jr. walked around in front of his sibling before staring her in the eyes.

Jr. couldn't help the slight laugh that came out of his mouth as he saw the tiny amount of confusion in Mimi's largely blank expression before he gently caressed her face allowing his thumb to rest on her lips as he spoke.

"Please give me a moment I am new to using this ability so don't blame me if I brush something from under the mat." Jr. focused and began feeling around for Mimi's sins specifically gluttony or rather the target of her gluttony Jr. smiled as he found his target.

"Muffins it is then?" asked Jr. as he walked towards his door as he opened the door he looked back at the two in the room a smile on his face as he spoke again.

"Don't destroy my room or kill each other but do feel free to tear some cloths off if a fight does breakout." said Jr. as he gave a small laugh before closing the door behind himself as he made his way to the kitchen.

Jr. hummed a small tune to himself as he walked the halls of his home occasionally nodding to the guards with a slight smug smile stretched across his lips.

Once he reached the kitchen he politely (ordered) the cooks to make two dozen muffins while waiting Jr. shuddered as a wave of wrath washed up from below most likely his mother or father…Jr.'s smile grew as he bathed in the almost tangible hate.

After a moment Jr. became bored of waiting and requested that once the muffins are finished that they be brought to his room before making the trek back to his room where on approach Jr. again felt wrath rolling out of his room along with the faint noise of scuffling.

Jr. cautiously opened his door despite his new partial devil nature he almost had a nose bleed the two girls were fighting throwing punches and the like along with kicks and the stray hair pull on occasion and somehow they had begun tearing at each other's cloths.

Jr.'s smile became a bit more perverse as he formed eight deep crimson tentacles which Jr. immediately launched at his sisters before wrapping them around their bodies.

Jr. closed his eyes and savored the feeling of their exposed skin before he opened his eyes and spoke "The muffins will be done soon Mimi…" Jr. tilted his head slightly as he looked at his sisters before he continued "Now would either of you be so kind as to enlighten me as to what caused the fight?"

MiniMandy frowned and looked away a slight blush on her face as the tentacles squirmed across her body.

Jr. sat there in silence waiting for an answer for a good minute before he began to get impatient and tightened his grip slightly causing one girl to squirm in discomfort and the other…in slight pleasure.

This was the scene one of the skeleton cooks walked in on which made everyone freeze in shock as the cook took in the view…the prince pinning his younger half-sister and other his half-sister/pet/slave with his tentacles the skeleton blushed and a bit of blood dripped from its nose hole as it set the tray of muffins on the nearest stand.

Once that was done it rushed back to the door and but before it exited it turned back to Jr. and gave him a thumbs up before leaving the room closing the door as it went before it rushed off to tell it brethren about what it saw.

Jr. and his siblings watched with wide eyes a few seconds before Jr. turned back to his half-sisters with a smile before speaking "20 bucks says that obscene rumors will begin spreading throughout the castle…any takers?"

The two girls looked at one another, the ragdoll with an embarrassed expression and the other blank as freshly made paper before both shook their heads negatively both were brought up to not be idiots or take bets on the obvious.

Jr. smirked at them before speaking "Well I wouldn't mind making some part of the rumors true…but first tell me why you were fighting."

Minnie frowned and spoke "Your red's former host refused to listen to me when I told her of her place."

Jr.'s smirk grew a little as he replied "Oh and where is her place?" Minnie spoke conviction tinting her words.

"She is beneath me!" Jr. gave a small smile at that and moved closer while also pulling the girls closer putting a hand under both of their chins.

"Both of you are going to be beneath me at one point or another so it doesn't really matter." stated Jr. carelessly as his hands trailed down to their collar bones.

Jr. suddenly withdrew his hands and tentacles "However, before that I would like you to be a bit healthier Mimi." as Jr. finished he looked at Mimi who had ran to the muffins as soon as she was released causing Jr. to chuckle at her before he turned to face Minnie who was rooted in place her face flush with scarlet.

Jr. moved after a moment and cupped Minnie's cheek "Would you like to get a head start on Mimi?"


	3. Chapter 3

Son of the underworld

I don't own Grim Tales

Grim tales AU idea by AkumaKami64

Jr. smiled as MiniMandy's blush grew and she looked at him with a bit of shock and…hope in her eyes and Jr. could almost see the lust hiding beneath her skin it was quite exciting.

Jr.'s smile became wider as flesh covered his form a mix of his Nergal and Red coming together to make him body to suit him.

It was remarkably similar to his soul form minus his still red and clawed hands, his hair a deep black with tints of crimson, a deep red tail trailed with spikes.

As MiniMandy took in her brother's appearance he surprised her and kissed her while also pushing her down slowly and getting on top of her with a smirk.

After a few more seconds Jr. broke the kiss and his smirk grew as he stared at MiniMandy her panting was rather enticing.

However Jr. pulled back and sat up leaving MiniMandy panting on the bed her blush covering the whole of her face and her body frozen his shock and pleasure.

Jr. had decided that he wouldn't do much more than that for now and when they finally did go along that path Jr. wanted her whining for him without the need for so much teasing or tapping her lust with his new found abilities so…he would be patient with her.

Jr. turned to look at Mimi only to raise an eyebrow at her…ravenous attacks on the muffins he couldn't help but smile as he eyed her with a few more years under the belt and a better feeding schedule she like MiniMandy would be quite the looker.

After a few more seconds of looking at his new pet he closed his eyes and focused looking for sins in the castle before a smile again spread across his face again this time carrying a more sadistic sense to it and he left MiniMandy on the bed and Mimi to finish her muffins while he tracked the source of his interest.

A few minutes in to his search he found what or rather who he was looking Dan the Phantom and from the looks of it he was getting ready to leave…Jr.'s smile lessened slightly and he called out to the phantom "Hey you with the flaming hair!"

Dan turned to look at the oddly familiar boy as he approached before he finally recognized the kid and Dan gave a smirk as he replied "Hey you're that shitty reaper's kid…what's with the new look?"

Jr.'s eye twitched slightly and he gave an agitated smile "Well…Phantom let's just say some family history was dug up and something from my past well…for lack of a better word it clung to me." as Jr. spoke he moved one hand behind his back and formed an empty sphere before making an energy ball while also using his other hand to make crimson tentacles wave around in front of them both.

After a moment Jr. compressed the ball and formed another tentacle which took the compressed energy through Jr.'s body through his feet and into the floor where it detached from Jr. and moved behind Dan and waited there was no way Jr. would be able to kill Dan in the castle without a lot of collateral damage so the need for a quick kill was how Jr. was going to end this.

Dan just gave an arrogant smirk and replied "So you found out who your daddy is huh good for you." when he finished talking Dan turned around again intent on finally leaving when Jr. tapped him again.

Dan now scowling turned to the kid completely missing the small crimson tentacle that rose silently behind him with its tip beginning to faintly glow green and spoke "What brat?" Jr. just gave a cocky smile and that's when Dan felt it a sharp and sudden pain in his neck, his spine to be specific and he fell to the ground.

Dan couldn't even breathe as he watched a small but long tentacle slither over his body and merge back into Jr.

Jr. crouched and began to talk "First off my name is Grim Jr., second off I am going to eat you because one you piss me off, and finally the reason you can't feel anything below the neck is because I shot a concentrated beam through your spine severing it…I don't doubt that with time and proper care you might heal but as I said before I don't like you and you might cause problems for me later on and since mom has had her fun with you already she won't mind if I kill you… it was really just luck on my side that you were still inside the castle but I am rambling now let's get this over with."

Dan who was suffocating slowly look up at this boy… Jr. … his murder who was just smiling down at him as a large tentacle formed on Jr.'s back before a large mouth grew and lunged at him…within seconds he was within the mouth and a large set of teeth began pressing on his skull.

Jr.'s smirk grew wider as he felt the Phantom's soul get broken down and after a moment released a satisfied breath before he wondered into the kitchen leaving a decently sized puddle of ectoplasmic blood from where the beam had burned through the entirety of Dan's neck thus the bloody mess.

Jr. however left the mess alone after all one of the staff would take care of it and that little snack had awakened his appetite and as Jr. made his way to the kitchen he retracted his mouthed tentacle back into his body.

After a short walk Jr. made it to the kitchen and after a bit of thought decided on that day's special Demon heart soup with a side of fries.

It was a Grim Skull castle original made from the heart of a demonic elder bear beast with chili cheese sauce and ghost peppers raised near the flame lake a few miles west of the castle and the fries where…fries made from potatoes not really a lot of variation with fries between the human world and the underworld or at least that is what Jr. had been told in his earlier years by Grim.

After a ten minute wait Jr.'s meal was delivered to the dining room and the smell it gave off was exactly what Jr. needed to really get into his meal unfortunately his meal was interrupted by Pain.

As soon as Pain saw Jr. he bowed his head and spoke "My prince the queen wishes to see you immediately."

Jr. rolled his eyes no doubt she had seen him kill her most recent bed buddy but why would she call on him for it she usually didn't care for them once they had been…used.

Jr. after a moment of considering just finishing his meal got up and ordered one of the servants to make sure that his food was still warm by the time he got back before following Pain to his mother.

As Jr. followed Pain he couldn't help but smile when he noticed that the puddle of ectoplasm had already been cleaned one could really appreciate the stuff they did their jobs well.

After a few minutes of walking Pain stopped outside his parents' bedroom Pain stopped just short of the door and opened it for Jr. for which Jr. gave him a thankful nod before entering with the door closing behind him.

Mandy was staring at him still his her pink bra and panties her face was impassive as usual and her eyes gave nothing away but he could feel it or feel them rather he could feel her sins as well as the sins of the two she was now carrying ah what a thing to be able to feel not only their souls but their potential sins as well.

Jr. almost shuddered in delight and a brilliant idea popped through his head and he release thousands of microscopic pieces of himself into the air directing them to the two souls in his mother's body with specific orders in mind.

Suddenly Mandy snapped at him "Jr." It was enough to snap him from his thoughts for the time being and to draw his eyes away from her midsection and to her eyes apparently she had been talking to him but he wasn't paying attention to focused on his new siblings to be.

Mandy scowled "Why were you not paying attention Jr.?" Jr. in response smiled at her and he allowed his eyes to fall to her lower stomach before replying.

"You're pregnant…with twins." Mandy blinked at him a moment before placing a hand over her womb and hmmed.

"You can tell…is there anything else that you can tell me about them soul or otherwise?" asked Mandy as her face fell back to her usual blank stare again.

Jr. smiled at her it was gentle or at least compared to the smiles he had given recently "They are going to be girls." Jr.'s smile widened more as he mental remarked that he was going to make sure of it.

Mandy looked at him a little harder but when she couldn't find anything she backed off drawing her hand back before speaking again "You killed the Dan…the ghost why?"

Jr.'s smile became a bit malicious as he replied "You have cameras all around I listed my reasons before I ate him…for how muscular he was his soul was almost pitifully small I wonder if his kids will inherit that?" Mandy just raised an eyebrow at him feeling that there was more to the situation but waved him away for now.

Jr. smiled at his mother gave a mock bow and exited her room making sure to close the door behind himself as Pain had apparently left.

Mandy allowed a scowl to cross her face it was difficult to read Jr. now his mannerisms had changed and him having an actual face should have made it easier but nothing he was a sheet of blank paper.

As Jr. walked back to the dinner he passed his dad who was downing cyanide like a pro so much so that he would have bumped into Jr. on his current path as he walked as his head was tossed back.

Jr. moved to the side of his father's path changed into his skeleton form and stopped and gently grabbed his father's cloak and after one of his father's long strides it almost pulled the drunken Grim over Jr. couldn't help but mentally note that he was most certainly not drinking like a pro…maybe he needed more practice?

Grim now scowling turned to look at who had almost made him spill only to see his son and a drunken smile spread over his face "Jr. my boy!"

Jr. felt Grim's wrath almost flare for a moment so he slapped it down putting a temporary lock on it so that he could talk with his dad without Grim's anger interrupting.

"Hi dad could you come with me to the dining room for a moment?" asked Jr. doing his best to put on a convincing smile Grim just smiled back at his yes his boy thought Grim not Him not anyone else's but his…Grim still smiling nodded and followed his son to the dining room.

Whereas upon his arrival one of the servants placed his still hot meal back onto the table Grim seeing the food felt a bit peckish and ordered one of the servants to bring him some food as well.

Jr. and Grim sat at the table for a few moments in silence with Jr. thinking on how he wanted to announce that he had reaped his second person today and that it was Dan…Grim just sort of sat there and wobbled while taking sips from his glass of cyanide.

Jr. broke the silence by clearing his currently nonexistent throat thus getting his father's attention before speaking "I kill Dan…I reaped him."

Grim's entire posture went from drunken too stiff as a board and as he looked at his son a smile broke across his bone face "That's my boy reaping bastards like him!" seemingly overjoyed at the pricks death Jr. smiled it was nice seeing his dad smile even if it was a drunken almost delirious one.


End file.
